CN113545475A

CN113545475A - Gel, preparation method and application thereof

Info

Publication number: CN113545475A
Application number: CN202110835289.9A
Authority: CN
Inventors: 周玉; 任留; 余小英; 刘海燕; 吴浩; 吕金刚; 唐鹏
Original assignee: Sichuan Huiji Food Co ltd; Sichuan Nanxi Huiji Food Co ltd
Current assignee: Sichuan Huiji Food Co ltd; Sichuan Nanxi Huiji Food Co ltd
Priority date: 2021-07-23
Filing date: 2021-07-23
Publication date: 2021-10-26

Abstract

The invention provides a gel, a preparation method and application thereof, and belongs to the field of food processing. The preparation of the gel comprises the steps of preparing acid slurry by fermenting yellow slurry after bean curd bittern squeezing and preparing the gel by compounding with glutamine transaminase; the prepared gel is then used for preparing the soy protein isolate dried bean curd. The gel time of the gel process link in industrial production of the soybean protein isolate dried tofu prepared by the method can be shortened from 6-10h to 3-4h, and a firm gel structure can be obtained without thermal stabilization, so that the efficiency in the production process of products is greatly improved.

Description

Gel, preparation method and application thereof

Technical Field

The invention relates to the field of food, and relates to a gel, a preparation method and application thereof.

Background

Isolated soy protein is a generic term for various proteins in soybean, and is composed mainly of 2S, 7S, 11S, and 15S proteins, the most important of which are 7S-beta-hemispheric protein and 11S glycinin. The gel property is one of the most important functional properties of soy protein isolate, and has attracted considerable attention from researchers in recent years. Proteins are generally modified by physical techniques, chemical techniques and biological enzyme modification techniques, and the type of bond formation is controlled to improve gel stability.

The soybean protein isolate dried bean curd is a novel bean product which is prepared by taking soybean protein isolate as a main raw material, modifying the soybean protein isolate into soybean protein isolate gel by a biological enzyme modification technology, and then marinating, seasoning and sterilizing. The most commonly used biological enzyme in its modification process is transglutaminase (TG enzyme). TG enzymes are acyltransferases that catalyze the reaction of primary ammonia with glutamine side chain acyl groups on proteins or polypeptide chains. TG enzyme can catalyze the cross-linking and polymerization of protein molecules and molecules, and the formed gel is mainly cross-linked through covalent bonds, so that the gel formed by the protein molecules can more easily obtain better elasticity and strength. As a safe and effective enzyme preparation, TG enzyme is widely applied to the bean product industry.

Currently, the general process for industrially preparing the soy protein isolate dried bean curd by using TG enzyme as a gel agent is as follows: subjecting the soybean protein isolate to TG enzyme cold glue at 4-6 deg.C for 6-10h, performing heat stabilization at 75-85 deg.C to obtain stable soybean protein isolate gel, and marinating, flavoring, and sterilizing to obtain dried bean curd of soybean protein isolate. It can be seen that under the existing process conditions, the formation of the soy protein isolate gel requires 6-10 hours, and for industrial production, the time is too long, the energy consumption is high, the production efficiency is low, and thus the production cost is high.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a gelling agent and a preparation method thereof, wherein the gelling agent is improved in the prior art that a single transglutaminase is used as a gelling agent, and the gelling time is long (6-10 hours), and the transglutaminase is compounded with acid slurry water (the acid slurry water is prepared by fermenting yellow slurry water after bean curd is marinated), so that a compound gelling agent is obtained, the gelling time is shortened, and the gelling efficiency is improved.

The second purpose of the invention is to use the prepared gel for preparing the dried bean curd of the soybean protein isolate, and the two processes are simultaneously carried out by combining the gel process and the thermal stabilization process, thereby reducing the production links, lowering the energy consumption and saving the production cost.

The scheme of the invention is as follows:

a gel formulation comprising: glutamine transaminase and mordant water;

furthermore, the gel is prepared from glutamine transaminase and acid pulp water according to the weight portion ratio of 1.5-2.5: 100-150.

Further, the acid serofluid is prepared by fermenting and filtering yellow serofluid obtained by marinating and squeezing bean curd.

Further, the acid serofluid is prepared by fermenting the yellow serofluid at 30-38 ℃ for 24-48 h.

Further, the acid serofluid is prepared by fermenting the yellow serofluid and filtering through a 160-mesh sieve.

Further, the gel is yellow clear liquid.

A preparation method of the gel comprises the following steps:

(1) preparing acid slurry water: fermenting and filtering yellow serofluid obtained by marinating and squeezing bean curd to obtain acid serofluid;

(2) preparing a gel: mixing the acid slurry with glutamine transaminase to obtain gel;

further, the yellow slurry fermentation mode in the step (1) is as follows: fermenting at 30-38 deg.C for 24-48 h;

further, the filtering sieve of the filtering mode in the step (1) is 160 meshes;

further, the ratio of the acid slurry water to the glutamine transaminase in the step (2) is that the ratio of the glutamine transaminase: acid slurry water =1.5-2.5: 100-150;

preferably, the yellow slurry fermentation mode in the step (1) is as follows: fermenting at 38 deg.C for 48 h;

preferably, the addition ratio of the acid slurry water to the glutamine transaminase in the step (2) is 2:120 by weight.

The gel prepared by the invention is used for preparing the soybean protein isolate dried tofu, and the specific steps are as follows:

(1) mixing and chopping soybean protein isolate and water to obtain a first mixture;

(2) chopping and mixing the first mixture and soybean oil to obtain a second mixture;

(3) mixing the second mixture with modified starch to obtain a third mixture;

(4) mixing the third mixture with a gelling agent to obtain a fourth mixture;

(5) pouring the fourth mixture into a mold, and carrying out gel forming at constant temperature;

(6) mixing the fourth mixture formed by constant temperature gel forming, and sterilizing to obtain the soybean protein isolate dried tofu;

further, the water requirement in the step (1) is as follows: measuring the room temperature, using normal temperature water at the temperature of less than 25 ℃, and measuring the room temperature, more than or equal to 25 ℃, using water at the temperature of 2-4 ℃;

further, the chopping time in the step (1) is 4-6 min;

further, the chopping time in the step (2) is 2-3 min;

further, the chopping time in the step (3) is 2-3 min;

further, the chopping time in the step (4) is 1-2 min;

further, the chopping and mixing in the steps (1) - (4) are carried out in a chopping and mixing pot, and the rotating speed of the chopping and mixing pot is more than or equal to 3000 rpm;

further, the proportion of the soybean protein isolate, the modified starch, the soybean oil, the water and the gel in the steps (1) - (4) is 120:20-40:20-60:520-620:50-100 by weight ratio.

Further, the temperature of the constant-temperature gel in the step (5) is 57-60 ℃, and the time is 3-4 h;

further, the material mixing process in the step (6) is to carry out conventional material mixing according to the taste requirement;

further, the sterilization process in the step (6) is as follows: 115 ℃ and 121 ℃, and sterilizing for 20-30min under 0.17-0.2 Mpa.

The invention has the following beneficial effects:

1. aiming at the condition that single glutamine transaminase is used as a gel in the prior art, the invention compounds the glutamine transaminase and acid slurry (the acid slurry is prepared by fermenting yellow slurry after bean curd is marinated) to obtain a compound gel; compared with the method for preparing the soybean protein isolate dried bean curd by directly utilizing glutamine transaminase, the method shortens the time of the soybean protein isolate gel from 6-10h to 3-4h under the same gel condition (the cold gel: 4-6 ℃), and greatly improves the gel efficiency.

2. In the prior art, the process for preparing the dried bean curd with the isolated soy protein is carried out separately (firstly gelling and then heating for stabilization); the gel prepared by the invention is used for preparing the dried bean curd of the soybean protein isolate, and the gel process and the thermal stabilization process are organically combined together (the gel is thermally stabilized at the same time), so that the production links are reduced, the energy consumption is reduced, and the production cost is saved.

3. The gel is used for preparing the dried bean curd of the soybean protein isolate, and the gel is combined with the sequence and the method for chopping the raw materials of the dried bean curd of the soybean protein isolate, so that the texture of the dried bean curd of the soybean protein isolate can be optimal.

Drawings

FIG. 1 is a dried bean protein isolate of dried bean curd prepared in example 4;

FIG. 2 is a dried bean protein isolate of dried bean curd prepared in comparative example 4;

FIG. 3 shows a dried bean protein isolate dried bean curd prepared in comparative example 5.

Detailed Description

The scheme of the invention will be explained with reference to the examples. It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention. The examples are given for the particular techniques or conditions, according to the techniques or conditions described in the literature in the field or according to the product description. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products which are commercially available.

Example 1

Preparing a gel agent:

1. fermenting yellow serofluid obtained by marinating and squeezing bean curd at 38 deg.C for 48 hr, and filtering with 160 mesh gauze to obtain acid serofluid;

2. the gel is prepared by mixing glutamine transaminase and acid pulp water according to the weight ratio of 2: 120.

Example 2

Preparing a gel agent:

1. fermenting yellow serofluid obtained by marinating and squeezing bean curd at 30 deg.C for 24 hr, and filtering with 160 mesh gauze to obtain acid serofluid;

2. the gel is prepared by mixing glutamine transaminase and acid pulp water according to the weight ratio of 1.5: 150.

Example 3

Preparing a gel agent:

(1) fermenting yellow serofluid obtained by marinating and squeezing bean curd at 38 deg.C for 36h, and filtering with 160 mesh gauze to obtain acid serofluid;

(2) the gel is prepared by mixing the glutamine transaminase and the acid pulp water according to the weight ratio of 2.5: 100.

Example 4

Preparing the dried bean curd with the isolated soy protein:

1. preparing 110kg of soy protein isolate, 30kg of modified starch, 40kg of soybean oil, 550kg of water and 55kg of the gel prepared in example 1;

2. adding water into soybean protein isolate, chopping for 5min in a chopping pot with the rotation speed of more than or equal to 3000rpm, adding soybean oil, chopping for 3min, adding modified starch, chopping for 2min, adding gel, and chopping for 2min to obtain soybean protein isolate slurry;

3. pouring the chopped soybean protein isolate slurry into a mold, and heating the gel for 3.8 hours at the constant temperature of 58 ℃;

4. and (3) mixing the gelled soybean protein isolate and sterilizing to obtain the soybean protein isolate dried tofu.

Example 5

Preparing the dried bean curd with the isolated soy protein:

1. preparing 100 kg of soybean protein isolate, 20 kg of modified starch, 20 kg of soybean oil, 520 kg of water and 50kg of gel;

2. adding water into soybean protein isolate, chopping for 4min in a chopping pot with the rotation speed of more than or equal to 3000rpm, adding soybean oil, chopping for 2min, adding modified starch, chopping for 2min, adding gel, and chopping for 1min to obtain soybean protein isolate slurry;

3. pouring the chopped soybean protein isolate slurry into a mold, and heating the gel for 3 hours at a constant temperature of 57 ℃;

Example 6

Preparing the dried bean curd with the isolated soy protein:

1. preparing 120 kg of soybean protein isolate, 40kg of modified starch, 60 kg of soybean oil, 620 kg of water and 100 kg of gel;

2. adding water into soybean protein isolate, chopping for 5min in a chopping pot with the rotation speed of more than or equal to 3000rpm, adding soybean oil into the soybean protein isolate, chopping for 3min, adding modified starch, chopping for 3min, finally adding gel, chopping for 2min to obtain soybean protein isolate slurry;

3. pouring chopped soybean protein isolate slurry into a mold, and heating the gel for 4 hours at a constant temperature of 60 ℃;

4. and (3) marinating the well-gelled soybean protein isolate, mixing materials and sterilizing to obtain the soybean protein isolate dried tofu.

Comparative example 1

Only transglutaminase was chosen as gelling agent.

Comparative example 2

A gel was prepared as in example 1, except that: the ratio of glutamine transaminase to acid-plasma water in this comparative example was 1:80 by mass.

Comparative example 3

A gel was prepared as in example 1, except that: the ratio of transglutaminase to acid sludge water in this comparative example was 3:100 by mass.

Comparative example 4

The gel prepared in example 1 is used for preparing the dried bean curd of the soy protein isolate, and the preparation method is the same as example 4 and is different from example 4 in that: the gel time was 2h under constant temperature heating in this comparative example.

Comparative example 5

The gel prepared in example 1 is used for preparing the dried bean curd of the soy protein isolate, and the preparation method is the same as example 4 and is different from example 4 in that: the gel time was 8h under constant temperature heating in this comparative example.

Comparative example 6

The gel prepared in example 1 is used for preparing the dried bean curd of the soy protein isolate, and the preparation method is the same as example 4 and is different from example 4 in that: in the comparative example, the isolated soy protein, the modified starch, the soybean oil, the water and the gel are directly mixed and stirred.

Test example 1: gel time comparison of gels

The gel prepared in the example 1-3 and the comparative example 1-3 is used for carrying out gel treatment on the isolated soy protein, the gel temperature is the prior art cold gel temperature (4 ℃), the gel forming condition is judged according to the elasticity of the protein after the gel and the surface hardness of the embryo body, the observation is carried out once every 0.5h until the gel is formed, the gel time is recorded, and the results are as follows:

TABLE 1 gel time

。

From the above results, it is clear that (1) is the most preferable example; compared with the comparative example 1, the embodiment 1-3 shows that the gel obtained by compounding the acid plasma and the glutamine transaminase can obviously improve the gel time when the gel is used for carrying out gel treatment on the soybean protein compared with the mode of directly using single glutamine transaminase; ③ comparing the examples 1-3 with the comparative example 2.3, it is shown that the ratio of the acid-treated slurry to the transglutaminase is 1.5-2.5:100-150, the gel time can be significantly shortened, or the gel time can be reduced to a level lower than that required.

Test example 2: application of gel in quality analysis of soybean protein isolate dried tofu

1. Texture analysis

By analyzing the texture characteristics (hardness, chewing type and elasticity) of the dried bean curd of the soybean protein isolate, the quality of the dried bean curd of the soybean protein isolate prepared by different methods can be reflected.

(1) Test method

The dried bean curds obtained from the soybean proteins of examples 4 to 6 and comparative examples 4 to 6 were subjected to measurement by a TPA texture analyzer. The dried tofu is sampled by a sampler at the middle part of the dried tofu, the height of the dried tofu is 3cm, a TA35 probe is adopted, the testing speed is 1mm/s, the returning speed is 1mm/s, the deformation amount of the sample is 60%, the cycle time is 2 times, the testing time is 1.5s, and the pressure is 10.0 g.

(2) Test results

TABLE 2 results of texture analysis

。

(3) And (4) analyzing results: from the test results, it can be seen that example 4 has the best elasticity, the hardness is relatively moderate to the chewing type, the elasticity is relatively low for comparative example 4 and comparative example 5, the hardness and chewiness are relatively low for comparative example 4, which indicates that the texture is soft, and the hardness and chewiness are too high for comparative example 5, which indicates that the texture is hard, compared with comparative examples 4 to 5, and therefore, only the dried tofu prepared in the gel time disclosed in the present invention can obtain the better texture, and the short or long gel time affects the texture of the dried tofu; example 4 compared to comparative example 6, it is shown that the sequence and manner of addition of the raw materials of the dried tofu can also affect the texture of the dried tofu.

2. Sensory evaluation

The sensory evaluation of the dried bean curd with the isolated soy protein obtained in the examples 4-6 and the comparative examples 4-6 is respectively carried out on the aspects of color, texture, smell and taste, and the quality of the dried bean curd with the isolated soy protein and the acceptance of consumers can be visually compared according to the sensory evaluation result.

The test method comprises the following steps: the color, the tissue state, the smell and the taste of the product are evaluated in the modes of observation, touch and taste, and the evaluation is carried out in the mode of anonymous scoring, and the evaluation standard and the evaluation result are as follows:

TABLE 3 sensory evaluation criteria for soy protein isolate dried tofu

。

TABLE 4 sensory evaluation results

。

From the above results, it can be seen that example 4 is significantly superior to comparative example 4.5.6 in color, texture, odor and flavor, indicating that when the gelling agent is applied to the dried bean curd with soy protein isolate, the sensory quality is lowered due to the fact that the gelling effect is not achieved when the gelling time is too short or too long; meanwhile, the chopping sequence and the chopping mode of the raw materials also have influence on the sensory quality of the dried bean curd with the isolated soy protein, which shows that the product effect can be best only by adopting the chopping mode provided by the invention.

Experimental example 3 comparison of appearance and Structure of gel

The gel structure can be influenced by the length of the gel time, the isolated soy protein dried tofu prepared by the technical schemes of example 4, comparative example 4 and comparative example 5 is subjected to visual comparison by the prepared finished dried tofu, and the quality of the dried tofu is analyzed.

The physical figures of the prepared dried tofu are as follows (fig. 1 is the dried tofu prepared in example 4, fig. 2 is the dried tofu prepared in comparative example 4, and fig. 3 is the dried tofu prepared in comparative example 5):

as can be seen from the figure, the dried tofu prepared in example 4 has moderate flexibility, and the elasticity and hardness reach better levels; comparative example 4 is dried tofu obtained by gel 2h, and it can be seen from the figure that the dried tofu has a large degree of curvature and thus a soft texture; comparative example 5 is dried tofu prepared from gel 8h, and it is seen from the figure that it is less bent and thus has a hard texture, and it is seen from the bending that the dried tofu of comparative example 4 and comparative example 5 lose elasticity to some extent. Thus, only dried tofu made during the gel time disclosed in the present invention can achieve a better texture.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gel formulation, comprising: glutamine transaminase and acid serous fluid.

2. The gel of claim 1, wherein the gel is prepared from glutamine transaminase and acid plasma water in a weight ratio of 1.5-2.5: 100-150.

3. The gel of claim 1, wherein the acid slurry is prepared by fermenting and filtering yellow slurry water obtained by squeezing bean curd bittern.

4. The gel of claim 3, wherein the acid serous fluid is prepared by fermenting the yellow serous fluid at 30-38 ℃ for 24-48 h.

5. The gel of claim 3, wherein the acid slurry is prepared by fermenting the yellow slurry and filtering through a 160-mesh screen.

6. A process for preparing the gel of any one of claims 1 to 5, comprising mixing said physalis alkekengi and transglutaminase to obtain said gel.

7. Use of the gelling agent according to any one of claims 1 to 5 for the preparation of dried soy protein isolate.

8. The use of claim 7, wherein the gel is mixed with soy protein isolate, modified starch, soy oil, and water to prepare a soy protein isolate dried bean curd.

9. The use as claimed in claim 8, wherein the soy protein isolate, the modified starch, the soybean oil, the water and the gelling agent are mixed in an amount of 100-120:20-40:20-60:520-620:50-100 parts by weight.

10. The use according to claim 8 or 9, wherein the preparation method of the dried bean curd with soy protein isolate comprises the following steps:

(1) chopping and mixing the soybean protein isolate and water in a chopping pot with the rotating speed of more than or equal to 3000rpm for 4-6min to obtain a first mixture;

(2) mixing the first mixture with soybean oil, and chopping for 2-3min to obtain a second mixture;

(3) mixing the second mixture with modified starch, and chopping for 2-3min to obtain a third mixture;

(4) mixing the third mixture with gelling agent, and chopping for 1-2min to obtain a fourth mixture;

(5) pouring the fourth mixture into a mold, and standing at a constant temperature of 57-60 ℃ for 3-4h for gel forming;

(6) and stirring and sterilizing the gel-formed fourth mixture to obtain the soybean protein isolate dried tofu.